Studies on Milk-clotting Enzyme of Dothiorella ribis -Part II. Properties of the Enzyme-

Dothiorella ribis가 생산하는 응유효소에 관한 연구 -제 2 보 응유효소로서의 일반적 성질-

  • Kim, Yu-Sam (Department of Food Engineering, College of Science and Engineering, Yonsei University) ;
  • Hong, Yun-Myung (Department of Chemical Engineering, College of Science and Engineering, Yonsei University) ;
  • Yu, Ju-Hyun (Department of Food Engineering, College of Science and Engineering, Yonsei University)
  • 김유삼 (연세대학교 이공대학공학부 식품공학과) ;
  • 홍윤명 (연세대학교이공대학공학부 화공과) ;
  • 유주현 (연세대학교 이공대학공학부 식품공학과)
  • Published : 1971.12.28

Abstract

The amount of the milk clotting enzyme which is produced by Dothiorella ribis in wheat bran was 950 Soxhlet units per gram of wheat bran. The milk clotting activity of this enzyme was increased by the elevation of clotting temperature and by the increase of the addition of $CaCl_2$ to milk. It was also increased when the pH of milk was lower than that of the fresh milk. When milk was diluted by distilled water, the milk clotting activity of the enzyme was decreased. And its milk clotting activity was good when milk was pasteurized at low temperature. The enzyme of Dothiorella ribis has larger proteolytic activity per Soxhlet unit than that of the milk clotting enzyme of Mucor pusillus Lindt. This enzyme was rather stable between pH 6 and pH 8 when it was conditioned for ten minutes. The heat stability of enzyme was tested by treating it under the condition for $10{\sim}60$ minutes. And the enzyme was stable under the temperature of $45^{\circ}C$. Also the recovery of protein as a form of curd was 76.2 percent to the total protein content of milk.

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